Tilting-wing flying-boat.



Patented Dec. 10, 1918.

2 $HEETSSHEET I GLENN H Curamss.

ml m, runs on, rum; u. wumucmn. n c.

244. AERONAUTlCS G.-H. CUR'IISS. TILTING WING FLYING BOAT.

v I APPLICATION FILED DEC.2I. 1916- 1,287,249.

Patented Dec. 10, 1918.

2 SHEETS-SHEET 2.

Fla 2 SWUQ/MOZ GLENN HCuanss.

244. ALHUNHUHUQ UNITED STATE 515MB, QFFICE- GLENN H. CURTISS, or BUFFALO, NEW YORK, ASSIGNOR TO CURTISSQAEBOPLANE AND,

-1VLOTQR CORPORATION, A CORPORATION or NEW YORK.

TILTIN'G-WING- FLYING-BOAT.

To all whom it may concern:

Be it known that I, GLENN H. CURTIss, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Tilting-Wing Flying-Boats, of which the following is a specification.

My invention relates in general to flying boats and more particularly to the arrangement of the wings thereof so that rising from and alighting upon the surface of the water may be more easily and effectually accomplished. In its more specific embodiments my' invention pertains to that class of flying boats which are substantially straight of keel. Y

The difficulties attending proper rising from the water are often very great, par ticularly when rough water is encountered, since the pitching and rolling of the craft due to the effects of the waves causes a varying angle of incidence of the aeroplanewings which is unfavorable to making a proper break from the water surface. When the flying boat is at rest upon the surface of the water the position of the hull is such that the wings have almost a correct angle of incidence. However, as soon as sufficient speed is developed and the boat begins to hydroplane the forward portion of the hull rises out of the water and the rearward por tion is depressed. This position increases the angle of incidence of the wings to such a degree, however, that a further increase in speed of the boat is impossible due to the enormous head resistance offered by the wings at this angle. In order then to attain sufiicient speed for breaking away from the water surface it is the usual practice to set the elevators in a downward position so that they effectually lift the tail of the boat and tend to depress the nose thereof. This action so decreases the head resistance that a high velocity is attained, and when the proper velocity is reached the elevator is suddenly raised and the boat breaks awa from the water. The above procedure is not possible, however, with flying boats in which the hull is of such construction that the keel is straight or substantially straight, since in this type of boat the underneath hydroplaning surface is so long, and even while the boat is skimming remains in contact with the water zontal plane.

Specification of Letters Patent. Patented Dec, 10, 1918 Application filed December 21,1916. Serial No. 138,275. 1

for so great a distance that the boat itself cannot be longitudinally rocked to rise.

My invention overcomes the above mentioned objections by providing a wing or set of wings so constructed that their angle of incidence may be varied at will with regard to the hull of the flying boat and independently of the position thereof. Hence it is possible to maintain any desired angle of incidence for the wings or planes irrespective of the condition of the hull of the boat due to the combined effects of rough water and the hydroplaning action of the underneath portion of the hull. To this and other ends I herein disclose the features of my invention in three of its embodiments, all of which, however, serve to accomplish the same desired results.

Figure 1 is a side elevation of one embodiment of my invention;

Fig. 2 is a front elevation;

Fig. 3 is a perspective view of a second embodiment of my invention;

Fig. 4 is a partial side elevation thereof;

Fig. 5 is a side elevation of a third embodiment of my invention; and

Figs. 6 and 7 are details of the pivotal support used in the above embodiments.

The construction of the hull 10 is such that the longitudinal extent of the underneath portion of the hull extends along a straight line and lies in a substantially hori- It is here shown including three or four steps 13, all of which lie along the line AA as in Fig. 1. However, it is not necessary that any particular number of steps be used. The wings 11 to which are rigidly attached the outriggers l4 and 15 which serve to support the tail structure, are pivoted at the points 16 in such manner that the center of gravity of the boat and the center of pressure of the aeroplane wings 11 will fall slightly aft of the pivotal supporting point. The object of thus sup porting the wing structure will be more clearly pointed out later. In order to vary the angle of incidence of the wings 11, I' have provided a cable 17 which is attached at the point 18 to the wing structure. Passing from the point 18, the cable 17 is led over a drum or pulley 19 from which point it is carried within the hull 10 to a drum and ratchet wheel 20. From this point it is extended, still within the hull, to and over a pulley 21, and thence to a point 22 on the lower outrigger 15. The location of the point 22 is such that its radial distance from the pivot point 16 is equal to the distance of the point 18 from the pivot point 16. This is necessary in order that no slack or undue tautness may come upon the cable 17 by reason of its change of position. The lower wing 11 is provided at its forward end with a bearing surface 23 which bears upon the point 24 of the hull 10. This contact of the wing surface with the hull serves to pre vent decreasing the angle of incidence of the wing below a certain predetermined minimum value while hydroplaning upon the water surface.

Suppose it is desired to increase the angle of incidence of the wings subsequent to hydroplaning action, speed having been at tained. It is only necessary to operate the drum and ratchet 20 by means of the lever 25 which carries a pawl to engage the ratchet. This action will pull down upon the outrigger 15 and due to the pivotal sup porting of the wing structure upon the hull at the point 16, the angle of incidence of the wings will be increased to any desired value within certain limits. The construction of the ratchet and pawl is such that the drum may be locked in anv desired position to give any desired angle of incidence to the wings or the pawl may be kept in disengagement with the ratchet thereby permitting the hull to assume a streamline position while in the air. The craft having gotten into the air, the wind vane action of the air upon the rearmost portion of the hull is sutficient to cause it to trail in the streamline, thus presenting a minimum amount of head resistance to flight. In this position, the wings will be approximately in constant contact with the bearing surface 24 above referred to. V

In the second embodiment of my invention as shown in Fig. 5, the wings 11 have rigidly attached Outriggers 14 and 15 supporting the vertical stabilizer 26. the horizontal stabilizer 27,'the vertical rudder 2S, and the elevators 29. As in the previous embodiment, the wing structure is pivotally supported to the hull of the boat 10 by means of the pivot 16. In both cases the center of gravity of the boat hull and the center of pressure of the wings lies aft of the pivotal supporting point 16 in order to maintain the bearing point 24 of the hull in contact with the wing surface 23. The boat hull 10 carries at its rearmost portion the water rudder 30 which the head resistance.

However, as soon as speed has been reached the elevators 29 are lifted from their depressed position whereupon the entire empennage is depressed due to the downward action of the air upon the upper surface of the elevators. Since the empennage is rigidly attached to the wing structure by means of the Outriggers 14 and 15, the wings '11 will. be given an increased angle of incidence by reason of the fact that they are pivotally supported at 16. This increased angle of incidence will increase the lift on the aeroplane wings to such an extent that the craft will be lifted free from the water surface whereupon the elevators may be returned to the normal position of horizontal flight.

In another embodiment of my invention as shown in Fig. 3, the hull 10 supports at its forward portion an aeroplane wing structure wholly designated as 31 and at its rearmost portion the usual horizontal stabilizer 32,'vertical rudder vertical stabilizer 34 and elevators 35, the empennage being rig-v idly braced to the boat hull by means of the bracing members 36...The wing-structure wholly designated as 31 comprises a lower. plane 37 and an upper plane 38, the lower plane 37 being rigidly attached to the hull in such manner'that its angle of incidence with respect thereto is invariable. The upper wing, however, is composed of a number of sections 39, 40,41, 42 and 43. The central,

section 41 is rigidly attached to the hull and lower wing structure by means of the struts or supports 42, its angle of incidence being invariable. The outer wing sections 39, 40, 42 and 43, however, are pivotally supported at the points 44 in such manner that their. angle ofincidence may be varied at will. The cables 45'carried at the rear ofthese' movable panels lead from pulleys 46 to a point within the boat hull 10 where they may be operated by any suitable means.

, It will be noticed that the construction of the wing posts 47 and 48 is of the form of an inverted V having at its apex a series of pivot points 44 to which the upper wing panel is attached. The lower extremities of the members 47 and 48 are carried in the usual wing post sockets 50 secured to the lower plane. wing sections above referred to, the machine may also be equipped with ailerons 51 although these are not necessary for the maintenance of lateral stability by reason of the fact that either one or all of the movable wing sections may be operated either sepa-. rately and independently or simultaneously. In the event that the outer sections 39 or 43 are operated independently of the rest of the wing, the same effect would be obtained as with the use of the ailerons.

The operation of this embodiment is' very similar to that described in the previous em-.

In addition to the movable Z l h HEliUNHU l IUD bodii'nenfts. The upper wing sections are set to their minimum degree of incidence until speed is obtained on the water surface and at the proper time the upper wing sections are pulled down at therear bv the operating cables '45 whereupon: the angle of incidence and consequently the lift is increased to such a point that the boat will break away from the water surface.

Fig. 7 is a view showing one form of constructing the pivot support for the wing structure described in the first two embodimerits. Preferably the central wing section is built up of metal ribs 52 carried between the lower wing beams 53 and 54. This central rib 52 carries integrally formed therewith a bracing channel 55 which serves to retain the pivotal bearing 56, the leading edge 57 and the trailing edge 58, the latter being fixed to the beams in any desired manner. Fig. 6 is a fragmentary side view of the pivot support just-described. The general arrangement of the pivot supporting means is clearly set forth in front elevation of Fig. 2 in which the function of the pivot bracing members'59 and 60 is clearly shown.

In thus disclosing my invention, I am fully aware that the idea of a variable angle of incidence wing has been previously set forth, for instance in a patent to Roche, 1,083,464, and others. I do not claim this. My invention consists of a combination of elements, of which the variable angle of incidence is one, although any desired form of variable incidence may be used in the combination.

By the use of the word non-salient in connection with the hydroplaning bottom of the hull, I distinguish from salient. All practical machines, up to this time, have relied upon fore and aft oscillation. To effect such oscillation the bottoms of previous hydro-aircraft have been characterized by fore and aft saliency. The bottom construction of the craft of this invention is conversely characterized, 11. c. it is non-salient throughout that portion of its length in the vicinitv of the transverse vertical plane of the center of gravity. Such interpretation should be given the word non-saliency in construing both specification and claims.

Although I have utilized certain detailed forms in disclosing my invention, I do not consider that the spirit or principle is limited thereby since minor variations in construction may be made without departing from the principles herein set forth. Furthermore, my invention is equally applicable to flying boats of single step or multiple step hydroplane types or to flying boats consisting of either one or any plurality of wings or planes in different superposed combinations.

What is claimed is:

1. In a flying boat, a hull having a hydroplaning bottom characterized by fore and aft non-saliency, aeroplane wings, an empennage carried above the hull and rigidly connected with the aeroplane wings, and operable means for varying the angularity of said wings relative to said hull without disturbing the longitudinal trim of the hull in arising from and alighting upon the water surface.

2. In a flying boat, a hull having a hydroplaning bottom characterized by fore and aft non-resiliency, an adjustable aeroplane wing structure mounted above the forward portion of said hull, an empennage, outriggers rigidly attaching the empennage to the wing structure and constituting a fuselage, and means adjustably attaching said fuselage to the forward portion of said hull to vary the relative angularity of said wing structure and said hull to effect breaking away from the water surface subsequent to hydroplaning, without disturbing the longitudinal trim of the hull relatively to the surface of the water.

3. In a flying boat, an elongated hull comprising the back bone of the craft, an aeroplane structure having a pivot axis extending transversely through the hull, an empennage movable with the wing structure and mounted directly above the tail end of the hull, and means for varying the angularity of said structure and said hull while the craft is in operation, such variation having no effect whatsoever on the longitudinal trim of the hull either in alighting upon or arising from the surface of the water.

4. In a flying boat, a wing structure, an empennage rigidly attached thereto, a hull pivotally suspended from said structure at a point nearer the prow than the stern so that in flight the trailing ortion of the hull follows automatically in the streamline, and mechanism inclosed in the hull for varying the angle of the wing structure relatively to the hull without disturbing the longitudinal trim of the hull either in alighting upon or arising from the surface of the water.

5. In a flying boat, a Wing structure, a connected empennage, a hull forming a support for said structure and empennage, a connection between the hull and wing structure so arranged and constructed that the variation in the angularity of the wings in no way disturbs the longitudinal trim of the hull, and means for limiting the degree of angularity of said wing and empennage structure with respect to the hull.

6. In a flying boat, a wing structure comprising forward wings and an empennage, and an elongated hull having a longitudinally non-salient bottom extending from a point in advance of the wing structure well to the rear of the craft, said hull being pivotally supported by the wings when in the air and pivotally supporting the wing structure While hydroplaning on the water surface.

7. In a flying boat, an elongated hull having a hydroplaning bottom characterized by fore and aft non-saliency, a Wing structure mounted on the forward portion of the hull, an empennage rigidly connected with the wings and overlying the rearward portion of the hull, and means for adjusting the angularity of said empennage with respect to the hull.

8. A flying boat comprising an elongated hull having a hydroplaning bottom characterized by fore and aft non-saliency, aeroplane wings mounted on the hull at an intermecliate point and pivotally connected thereto on a transverse axis, and adjusting mechanism connected With said Wings for moving them about said axis to effect a break from the surface of the Water without rocking the hull longitudinally.

9. A flying boat including a longitudinal Water borne hull having a hydroplaning bottom characterized by fore and aft nonsaliency throughout that portion of its length in the vicinity of the transverse vertical plane of the center of gravity, an adjustable supporting-Wing-structure mounted above that portion of the hydroplaning bottom thus characterized, and mechanism inclosed within the hull for varying the angularity of the wings, the variation in the angularity of the Wings obtained in this Way being relied upon to lift the craft from the surface of the Water Without recourse to oscillation fore and aft.

In testimony whereof I aflix my signature.

GLENN H. CURTISS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. 0." 

